Distance marker and mobile device case for distance measurement

ABSTRACT

A mobile device case or cover can include a distance marker for distance measurement. A mobile device coupled with the case may include a measurement application or module that can acquire video or still images of the distance marker. The measurement application can calculate a distance to the distance marker based on a captured image of the distance marker in the video or still images. The mobile device case can include a pocket, slot, or storage compartment for storing the distance marker.

INCORPORATION BY REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/405,843, filed Jan. 13, 2017, which is a continuation of U.S.application Ser. No. 14/944,023, filed Nov. 17, 2015, which is acontinuation of U.S. application Ser. No. 14/254,853, filed Apr. 16,2014, which claims benefit under 35 U.S.C. § 119(e) from U.S.Provisional Application No. 61/813,021, filed on Apr. 17, 2013. All ofthe above applications are hereby incorporated herein by reference intheir entirety and are to be considered a part of this specification.

BACKGROUND

With each new generation, portable electronic devices provide greaterfunctionality and have more capabilities. These portable electronicdevices allow people to play and record music, send and receive e-mail,send text messages, browse Web pages, make phone calls, play and recordvideo, take and view pictures, edit documents, and much more. Thesedevices continue to revolutionize the way people interact, learn,connect with other people, conduct business, and find information. Theyhelp people manage their daily lives and can be a source ofentertainment. These devices can be used to store valuable informationincluding personal information, such as phone numbers, financialinformation, private photos or videos, and favorite music tracks.

Typically these devices are intended to be carried or moved about. Assuch, these devices are more vulnerable to damage as compared tonon-portable devices. Portable electronic devices are more likely to beaccidentally dropped, hit, scratched, or water damaged. While some typesof damage may be cosmetic (e.g., scratches), other types of damage mayruin or limit the functionality of the device. Often these devicescontain sensitive and fragile components (e.g., screen, camera lens,flash memory, processors, accelerometers, and sensors). Accidentallydropping the device could render various features unusable. Accordingly,protective cases are often used to protect these devices from possibledamage.

SUMMARY

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of several embodiments have been described herein. Itis to be understood that not necessarily all such advantages can beachieved in accordance with any particular embodiment of the featuresdisclosed herein. Thus, the embodiments disclosed herein can be embodiedor carried out in a manner that achieves or optimizes one advantage orgroup of advantages as taught herein without necessarily achieving otheradvantages as can be taught or suggested herein. It should be understoodthat the various aspects, or features of the embodiment, herein may becombined.

In certain embodiments, a mobile device assembly includes a mobiledevice case that can at least partially cover a mobile device and adistance marker that can be coupled with the case. The distance markercan include an image that can be detected by a measurement module forcalculating a distance from the mobile device to the distance marker.

In various embodiments, a mobile device assembly includes a distancemarker having an image and a measurement module or application that canbe implemented by a mobile device and that can detect the image of thedistance marker. The measurement module or application can include adistance calculator that can calculate a distance from the mobile deviceto the distance marker.

In other embodiments, a mobile device assembly includes a mobile devicecase that can at least partially cover a mobile device and a measurementapplication that can be implemented by the mobile device and that candetect an image associated with the mobile device case. The measurementapplication can include a distance calculator that can calculate adistance from the mobile device to the image.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings, common reference numbers are used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate embodiments of the features described herein and not to limitthe scope thereof.

FIG. 1 depicts an embodiment of a mobile device configured to measuredistance.

FIG. 2 depicts a side perspective view of an embodiment of a mobiledevice case and distance marker.

FIG. 3 depicts additional views of the mobile device case and distancemarker of FIG. 2.

FIG. 4 depicts perspective views of an embodiment of a distance markerand mobile device.

FIG. 5 depicts a side perspective view of another embodiment of a mobiledevice case and distance marker.

FIG. 6 depicts additional views of the mobile device case and distancemarker of FIG. 5.

FIG. 7 depicts an embodiment of a mobile device including a cameramodule and a measurement module.

FIG. 8 depicts an embodiment of a distance measurement process that canbe implemented by the camera module and the measurement module of FIG.7.

FIGS. 9 and 10 depict example measurement user interfaces of a mobiledevice.

DETAILED DESCRIPTION

I. Introduction

In addition to protecting a mobile device, protective cases or coverscan also enhance the functionality of the mobile device. Many cases, forinstance, include a kick-stand or fold into a shape that permits themobile device to be propped up into a more comfortable typing position.Other cases can hold a stylus when a stylus is not being used by a user.

This disclosure describes embodiments of a mobile device case or coverthat include a distance marker for distance measurement. A mobile devicecoupled with the case may include a measurement application or modulethat can acquire video or still images of the distance marker. Themeasurement application can calculate a distance to the distance markerbased on a captured image of the distance marker in the video or stillimages. In one embodiment, the mobile device case includes a pocket,slot, or storage compartment for storing the distance marker.

The embodiments disclosed herein are described primarily in the contextof a case and distance marker for a mobile phone or smartphone becausethe embodiments disclosed herein have particular utility in thiscontext. However, the embodiments and features described herein can alsobe applied to other types of mobile devices, including, but not limitedto tablets, laptops (including ultrabooks and netbooks), combinationlaptop/tablets, electronic book readers (e-readers), personal digitalassistants (PDAs), portable game devices and game controllers, musicplayers (e.g., MP3 players), digital cameras, portable digital recordersor Dictaphones, or any other portable electronic device.

II. Example Cases and Distance Marker

FIG. 1 depicts an embodiment of a mobile device 100 configured tomeasure distance. In the depicted embodiment, the mobile device 100 is amobile phone, such as a smartphone or the like, that can include acamera 103 that is able to take video or still images of a scene 110. Inthe example scene 110 shown, a person 102 is holding a distance marker120. A camera 103 in the mobile device 100 (shown in phantom torepresent that the camera may be on the back of the mobile device 100)captures and produces a picture or visual representation of the scene110 for output to a display 112 of the mobile device.

In certain embodiments, the mobile device 100 includes or accesses ameasurement application that analyzes the image or video obtained by thecamera 103 to detect the distance marker 120. In the depicted display112 of the mobile device 100, an image 122 of the distance marker 120 isshown in a hand of the person 102. The measurement application cananalyze the image 122 of the distance marker 120 in comparison to astored image of the distance marker 120 to ascertain a distance from themobile device 100 to the distance marker 120. In the depictedembodiment, the display 112 outputs a distance of 4.8 feet from themobile device 100 to the distance marker 120.

A user interface control (or button) 114 on the display 112 enables auser to initiate distance measurement by pressing the button 114. In anembodiment, the mobile device 100 includes a touch screen display 112,in which case the button 114 may be a touch screen button 114. Userselection of the touch screen button 114 can cause the measurementapplication to obtain video or a still image of the scene 110 andcalculate a measurement from the mobile device 100 to the distancemarker 120 in the scene 110.

In an embodiment, the measurement application analyzes captured videofrom the camera 103 to calculate the distance dynamically as a user 107moves the mobile device 100 relative to the scene 110. For example, asthe user 107 moves the mobile device 100 toward the scene 110, themeasurement application can calculate a decreasing distance to themarker 120 (assuming that the marker 120 stays in the same position).Likewise, as the user 107 moves the mobile device 100 away from thescene 110, the measurement application can calculate an increasingdistance to the marker 120 (assuming that the marker 120 stays in thesame position).

In the depicted embodiment, the mobile device 100 is partially coveredby a case 104 that can provide protection to at least a portion of themobile device 100. In an embodiment, the case 104 includes a pocket,slot, or storage compartment for receiving and storing the distancemarker 120, enabling a user 107 to easily carry the distance marker 120together with the mobile device 100. Examples of cases having a slot orpocket for holding the distance marker 120 are described below withrespect to FIGS. 2 through 6.

Advantageously, in certain embodiments, the measurement application ofthe mobile device 100 and the associated distance marker 120 can be usedto measure distances of a variety of lengths or ranges. In particular,in some embodiments, the distance marker 120 may be particularlyaccurate for measuring shorter distances, such as about 2 meters orless, about 4 meters or less, or about 8 meters or less, although longerdistances or shorter distances may also be measured with a high degreeof accuracy.

In addition, in some embodiments, the measurement application of themobile device 100 can use a separate long distance algorithm thatcalculates longer distances to objects. This long distance algorithmdoes not use the distance marker 120 in some embodiments. Such analgorithm can take into account the height and angle of the camera whilethe camera is aimed at the base of a target image. The height of thecamera may be assumed or may be input by the user, and the angle may bedetected by a gyroscope or accelerometer. The measurement applicationcan use trigonometry to detect the distance based on the user's height(which also may be input by the user), the height of the camera 103, andthe angle of the camera.

In an embodiment, the measurement application implemented by the mobiledevice 100 can be implemented in a processor, memory, or other hardwareof the mobile device 100. The measurement application is described ingreater detail below with respect to FIGS. 7 through 10.

Turning to FIG. 2, a more detailed embodiment of a case 204 and adistance marker 220 are shown. The case 204 corresponds to the case 104described above, and the distance marker 220 corresponds to the distancemarker 120 described above. The case 204 is generally rectangular andshaped to fit a mobile device such as the mobile device 100. Inparticular, the case 204 is shaped to fit a mobile phone, although thecase 204 may be adapted to fit devices other than a phone as describedabove. When placed inside the case 204, a phone or other mobile devicecan fit snugly, although the user may still have access to a display andother buttons of the mobile device via cutouts 260 and depressiblebutton covers 270 and 280 (see FIG. 3) of the case 204. Examples ofmobile phones for which case 204 may be configured to receive includethe iPhone™ available from Apple Computer™, various versions of Android™phones, and various versions of BlackBerry™ phones.

The case 204 includes four corners defined by a side support 241 and aback panel 230 that includes a top portion 232 and a bottom portion 234.Connecting the top and bottom portions 232, 234 is a connecting portion236 that has a width less than a width of the top portion 232 and thebottom portion 234. The top portion 232 and bottom portion 234 of theback panel 230 include tactile surfaces that provide a secure grip for auser's hands.

An inner panel 242 together with the back panel 230 desirably form apocket 240 that is adapted to receive and retain the distance marker 220for storage. The upper or top portion 232 of the back panel 230 and thebottom portion 234 of the back panel 230 desirably overlap the innerpanel 242 to create a slot or pocket 240 into which the marker 220 canbe securely stored. A finger cutout 250 defined by the top portion 232,the connecting portion 236 and the bottom portion 234 desirably providesa void or space in which a user may slide his or her finger onto themarker 220 when inserted into the pocket 240 to pull the marker 220 outof the pocket 240 as indicated by the arrow 201 (see also FIG. 3).

The case 204 also desirably includes a side void 244 defined by the sidesupport 241 and the inner panel 242. The side void 244 can receive abase 224 of the marker 220, which base 224 may include one or moremagnets for coupling with the side of the mobile device when insertedinto the case 204. The side void 244 can therefore facilitate themagnetic coupling of the base 224 of the marker 220 to the mobiledevice. This magnetic coupling mechanism is described in greater detailbelow with respect to FIG. 4.

In certain embodiments, the case 204 may be a hard case or a soft case.If the case 204 is a hard case, the case 204 may be made of aluminum,plastic, carbon fiber, or some other hard metal or synthetic materialfor protection of the mobile device. The case 204 may also be a softcase made of leather or a composite material that is more flexible thana hard case but which still may protect the mobile device. The case 204can also include both hard and soft materials, for example, with a hardexterior case for shielding from impacts and soft interior lining toabsorb impacts.

In an embodiment, the case 204 may be made of a polymeric or plasticmaterial. Such materials may include rubber, silicon, thermoplasticpolyurethane (“TPU”), cross-linked ethylene propylene diene class rubberpolypropylene polymers such as Santoprene® available from ExxonMobil,and/or other suitable thermoplastic or thermoset elastomeric polymersand copolymers. The case 204 may be made of a material that is suitablyflexible to allow a mobile device to be resiliently received and snuglyretained within the case 204. Additionally, the case 204 materials alonemay be impact resistant enough to resist fracture or permanentdeformation when the case 204 containing a mobile device is dropped froma user's hand, a table, a desk, and similar heights onto a variety ofsurfaces including concrete, asphalt, carpet, and the like. Such aheight may include heights such as six feet, five feet, four feet, threefeet, and the like.

The marker 220 includes a main body 222 and the base 224 describedabove. The main body 222 is generally rectangular or square in shape.The base 224 is also generally rectangular in shape. Either the mainbody 222 or the base 224 may have rounded edges. The base 224 has awidth that corresponds to a width of a phone or a mobile device insertedin the case 204. The marker 220 may be made out of any of the samematerials used to make the case 204 or may be made of differentmaterials. In an embodiment, the marker 220 is made primarily ofplastic.

The main body 222 of the marker 220 includes a tracking image 226 whichmay be adhered to the main body as a sticker or the like, screen-printedor painted on, and/or integrally formed with the main body 222. Theimage 226 includes various features that can be detected by an imageprocessing algorithm or module so as to measure distance. In anembodiment, some characteristics of the tracking image 226 includefeatures that are sharp, spiked, or otherwise chiseled details which maybe more easily trackable than rounded edges for instance. In addition,rich detail, high contrast, few or no repetitive patterns and evenlydistributed features in the tracking image 226 can facilitate easierdetection of the tracking image 226 and subsequent measurement. In thedepicted embodiment, the tracking image 226 includes a black and whiteimage of grass blades and bark (or approximate versions thereof), whichinclude many features, high contrast, rich detail, and the like. Thetracking image 226 can be detected by a variety of image processingmodules including, for example, the following image processing modulesor augmented reality modules: Vuforia™, Metaio™, Dlusion™, Layar™, andAR Lab™, among others.

In certain embodiments, the pocket 240 defined by the back panel 230 andinner panel 242 can provide a friction fit for the marker 220. Thus,when the marker 220 is slid into the pocket 240, a tight or somewhattight fit between the inner panel 242 and the back panel 230 can holdthe marker 220 snugly in place, although the marker 220 may also berelatively easily removed by a user pulling on the marker 220 throughthe finger cutout 250. In some embodiments, the finger cutout 250 isoptional. Further, a friction fit between the inner panel 242 and backpanel 230 of the case 204 is also optional, as one or more magnets maybe attached to the marker 220 to allow the marker to connect to themobile device easily as will be described in greater detail below. Bothmagnets and friction fit may be used in other embodiments to retain themarker 220 in the case 204. Although not shown, a strap or clips orother retaining mechanism may also be used, alone or in combination, toretain the marker 220 in the case 204.

Turning to FIG. 3, various additional views of the mobile device case204 and distance marker 220 of FIG. 2 are shown. In contrast with FIG.2, in FIG. 3, the marker 220 is shown inserted into the case 204. Themobile device case 204 is shown in a rear view 204 a, a left side view204 b, a right side view 204 c, a top view 204 d and a bottom view 204e. In the particular embodiment shown, the marker 220 is inserted intothe pocket 240, and in the side view 204 b the base 224 is thereforeshown on the side of the case 204 b. As shown, the base 224 of themarker 220 is flush or approximately flush with the side support 241 ofthe case 204 a. Further, as described above with respect to FIG. 2, thecase 204 as shown in the right side view 204 c and top view 204 dincludes depressible button covers 270 and 280 to cover volume controlbuttons and a power button, among other features.

In other embodiments, instead of having an opaque back panel 230 asshown, the case 204 may include a back panel 230 that is transparent ortranslucent. A transparent or translucent back panel 230 can allow thedistance marker 220 to be seen through the case 204. Consequently, thecase 204 may be detached from the mobile device and propped against anobject to be measured, and the camera of the mobile device can detectthe distance marker 220 in the case to measure distance. In still otherembodiments, the tracking image is integrated with the case 204,eliminating the use of a marker 220 entirely. For example, the trackingimage 220 can be a sticker or other material that is adhered to the case204 or that is integrally printed with the case 204. A user can removethe case 204 from the mobile device, set the case 204 near an object tobe measured, and activate the measurement application to measuredistance to the case 204.

Turning to FIG. 4, example perspective views of an embodiment of adistance marker 420 and a mobile device 400 are shown. In the depictedembodiment, the marker 420 is shown in three different views, includinga marker 420 a attached to the mobile device 400, a front perspectiveview of a marker 420 b, and a rear perspective view of the marker 420 c.The marker 420 includes all the features of the marker 220 and 120described above.

Like the markers described above, the marker 420 includes a main body422, a base 424, and a tracking image 426. Advantageously, in thedepicted embodiment, an inner surface 423 of the base 424 has magnets428 disposed thereon. These magnets 428 can magnetically couple with themobile device 400 when the base 424 of the marker 420 is brought intocontact with the mobile device 400. As described above with respect toFIG. 2, a side void 244 in the case 204 exposes a portion of the side ofthe mobile device, which can therefore come into contact with themagnets 428 of the base 424. For a mobile device that has metal on itsside or sides, the magnets 428 can magnetically attract to this metal tosecure the marker 420 against the mobile device.

The magnets 428 can be any type of magnet, such as rare-earth magnetsfor a strong magnetic field and hence tight fit to the mobile device400. The magnets 428 are thin in one embodiment to avoid causing themarker 420 to protrude from the case 204. For example, the magnets 428may be less than 1 mm thick, or less than about 2 mm thick, or the like.

In the depicted embodiment, the marker 420 includes a side wall 425 ofthe main body 422, which can have a thickness of about 1 to 2 mm (oranother thickness) to facilitate a flush fit or approximately flush fitwith the case 204. As a result, the marker 220 does not protrude beyondthe side support 241 of the case 204 in some embodiments. The thicknessof the base 424 can be the same as or similar to the thickness of theside wall 425 or may be a different thickness. For example, a side wall427 of the base 424 can have a thickness of about 1 to 2 mm or less than1 mm (or more than 2 mm).

The dimensions of the main body 422 can be approximately 2.5 cm inheight by 2.5 cm in width, with a thickness described above. In oneembodiment, the size of the main body 422 can range from about 2 cm by 2cm to about 8 cm by 8 cm but may also be smaller or larger. In oneembodiment, a smaller marker 420 is used for mobile devices 400 that aresmaller, such as phones, and a larger marker 420 can be used for largermobile devices, such as tablets and laptops.

Although the marker 420 is shown having a main body 422 that isgenerally square in shape, the main body 422 need not be square but caninstead be rectangular, circular, triangular, or any other shape,including a free form shape. In one embodiment, the marker 420 is in theshape of a licensed, branded or copyrighted character, or otherwhimsical shape to facilitate increased user enjoyment and use of themarker 420.

Turning to FIGS. 5 and 6, another embodiment of a mobile device case 504and distance marker 520 are shown. The distance marker 520 can includeall of the features of the markers 120, 220, 420 described above. Forexample, the marker 520 includes a main body 522, base 524, and trackingimage 526. The marker 520 may also include one or more magnets disposedon any surface thereof (see FIG. 4).

The case 504 can also include most or all of the features of the cases104, 204 described above. For example, the case 504 includes a backpanel 530 having an upper panel 532 and a bottom panel 534 as well as aconnecting portion 536. A pocket 540 is defined by the back panel 530and an inner layer 542 of the case 504, and a side support 541 is alsodefined around the edge of the case 504. The upper panel 532, bottompanel 534, and connecting portion 536 define a finger cutout 550. Themarker 520 may be inserted into the pocket 540 and removed by a userpressing a finger against the marker 520 using the finger cutout 550.Likewise, the case 504 includes an aperture 560 for the camera as wellas button covers 570 and 580 as shown in FIG. 6.

Of note, instead of having a side void 244 as in the case 204 of FIG. 2,the case 504 of FIG. 5 includes a side panel 544. The side panel 544extends downward from the inner panel 542 in place of the side void 244.Magnets or one or more magnets in the marker 520 can magnetize with orthrough the side panel 544 and/or the inner panel 542 to couple with amobile device inside the case (not shown). The side panel 544 may bemade (in part or in whole) of metal, for instance, to allow magneticcoupling with the marker 520 independently of whether the phone usedwith the case 504 does or does not have a metal side.

In addition, another difference shown is that the back panel 530 doesnot include the tactile portions such as the top and bottom portions 232and 234 of FIG. 2. However, the back panel 530 may be made of materialsuch as a polymeric or plastic material that provides a strong grip fora user.

In FIG. 6 various views of the case 504 are shown which correspond tothe same views of the case 504 (i.e., rear view 504 a, left side view504 b, right side view 504 c, top view 504 d, and bottom view 504 e) aswere shown with respect to the case 204 in FIG. 3.

III. Example Measurement Application

Turning to FIG. 7, an embodiment of a mobile device 700 is shown. Themobile device 700 can be any of the mobile devices described above. Themobile device 700 may include one or more physical processors able toprocess instructions that are stored on a computer readable storagemedium or the like. The mobile device 700 may also include memory,physical computer storage, and other hardware components.

In the depicted embodiment, the mobile device 700 includes a cameramodule 710 and a measurement module 720. In general, the camera module710 and measurement module 720 can include software and/or hardware forimplementing their respective features including, but not limited to,software, modules, code, and one or more processors or one or morememory devices. The camera module 710 and the measurement module 720 mayeach be considered an app or application. In other embodiments, eitherof the modules 710 and 720 can be implemented in a web browser usinghypertext markup language (HTML), cascaded style sheets (CSS), ascripting language such as JavaScript, combinations of the same, or thelike.

In certain embodiments, the camera module 710 is a stock camera moduleprovided with the mobile device 700 and captures still images and/orvideo. The camera module 710 can instead be a modified version of thecamera module provided with the mobile device 700. The measurementmodule 720 can communicate with the camera module 710 to obtain accessto images and/or video obtained from the camera module 710. Forinstance, the measurement module 720 may access video in real time as itis obtained from the camera module 710 or may access still imagesobtained from the camera module 710 after they are obtained.

The measurement module 720 can compute a distance from the mobile device700 to a distance marker, such as any of the distance markers describedabove. The measurement module 720 may compute this distance in real timeor substantially near real time based on the real time video framesobtained from the video of the camera module 710. Alternatively, a usermay take a picture with the camera module 710, and then the measurementmodule 720 can calculate the distance shortly thereafter, which may alsobe considered real time in one embodiment. For instance, the user maytake a picture of the distance marker using the camera module 710, andthe measurement module 720 may rapidly or immediately calculate thedistance from the mobile device 700 to the distance marker in the imagecaptured by the camera module 710.

In the depicted embodiment, the measurement module 720 includes adistance calculator 722 and an image processor 724. The distancecalculator 722 can include functionality for calculating distance basedon data obtained from the image processor or image processing module724. The image processing module 724 can include a software library orset of libraries that detect the marker in the image or video framesobtained from the camera module 710. For example, the image processingmodule 724 can include (or may call) a library provided by any of theimage processors described above (such as Vuforia™, Metaio™, Dlusion™,Layar™, or AR Lab™, among others). The image processing module 724 cancompare the distance marker in the image or video frame with a storedimage of the distance marker provided by the developer or provider ofthe measurement module 720. The distance calculator 722 can access dataprovided by the image processor 724 to calculate a distance based on aratio of the size of the captured distance marker to the stored distancemarker (or vice versa), with a greater ratio indicating closer distance(or vice versa). The image processor 724 may provide a distance value inimage processing units, which may be represented as pixels (or thewidth/length of pixels, even though the space between the camera and themarker does not include any actual pixels). In one embodiment, the imageprocessor 724 provides a distance vector, or alternatively, a matrixthat includes a column or row that represents a distance vector. Thedistance calculator 722 can convert this distance vector to standard orcommon distance units such as English customary units (e.g., feet andinches), metric units, or other units.

Turning to FIG. 8, an embodiment of a distance measurement process 800is shown. The distance measurement process 800 may be implemented by anyof the mobile devices described herein, including the mobile device 100,400, and 700. For example, the distance measurement process may beimplemented by the measurement application 720.

At block 802, of the process 800, the measurement module 720 receives avideo frame or image that includes an image of a distance marker. Themeasurement module 720 can receive this image from the camera module710. At block 804, the measurement module 720 can provide the frame tothe image processor 724. In response, the measurement module 720 mayreceive a distance vector at block 806. The distance vector canrepresent a distance from the camera to the distance marker, expressedin image processing units.

At block 808, the distance calculator 722 of the measurement module 720can compute a magnitude of the distance vector to obtain a distancevalue in image processing units. The distance calculator 722 convertsthe distance value to standard measurement units at block 810. In oneexample embodiment, the distance calculator 722 converts the distancevector to standard units using the following example code or the like:

floatdistance=sqrt(position.data[0]*position.data[0]+position.data[1]*position.data[1]+position.data[2]*position.data[2]);  (1)

float distInft=((distance*0.0328084/40)*8)/9;   (2)

int ft=distInft;   (3)

float inches=distInft-ft;   (4)

inches=(inches)*12.0f;   (5)

Expression (1) of the above code operates on a distance vectorrepresented as position.data[0] through position.data[2], which includesx, y, and z coordinate values. The distance vector represents orapproximately represents the distance from the camera to the distancemarker in one embodiment, where the camera (or the marker) is consideredthe origin in a Cartesian (or other) coordinate system. Expression (1)computes the Euclidean distance from the distance vector expressed asfollows:

distance=√{square root over ((x −x ₁)²+(y−y ₁)²+(z−z ₁)²)}  (6)

However, since the distance vector is represented with respect to theorigin (x₁=0, y₁=0, z₁=0), expression (6) and therefore expression (1)reduces to

distance=√{square root over (x ² +y ² +z ²)}  (7)

Expression (2) converts the computed distance in expression (1) fromimage processing units to a standard unit of measure, namely feet inthis example. Expression (3) obtains the integer value of the floatvalue obtained in expression (2), and expression (4) subtracts theinteger value from the float value to obtain the decimal value of thefloat value. This decimal value is converted to inches in expression(5). The feet and inches values can then be output by the measurementapplication 720 to a user. The measurement application 720 can insteadcompute metric units or other units based on the distance vector inother embodiments.

At block 812, the measurement module 720 outputs the distance value forpresentation to a user. Example user interfaces that output a distancevalue are shown in FIGS. 1, 9, and 10 (FIGS. 9 and 10 described below).At block 814, it is determined whether an additional frame or frames areincluded in the video, and if so, the process 800 loops back to block802, and otherwise the process 800 ends.

Turning to FIGS. 9 and 10, example user interfaces 900 and 1000 areshown. The user interfaces 900 and 1000 are implemented in a mobiledevice 901 and depict example output from the measurement application720 described above with respect to FIG. 7 and block 812 of FIG. 8. Inthe example user interface 900 results include an image of a marker 920.The marker image is different from the marker images described above. Inthis embodiment, the measurement application 720 has drawn an image of across on the marker, obscuring the marker but indicating where themarker was detected in the image. The measurement application 720 canuse OpenGL or another graphics library to draw any image on the markeror elsewhere on the display. For example, the measurement application720 can use a graphics library to draw a border around the detectedmarker or the like. In the example user interface 900 shown, the marker920 is placed on a wood surface 910, and the measurement from the mobiledevice 901 to the marker 920 is shown in box 930 as being zero feeteight inches.

In the user interface 1000 of FIG. 10, another type of marker 1020 isshown that is circular. The marker 1020 is also placed on the woodsurface 910, and the user interface 1000 shows a measurement from themobile device 901 to the marker 1020 of zero feet eight inches in box930.

IV. Additional Embodiments

Although the distance marker has been described herein as being coupledwith various example cases, the distance marker may also be providedwith, attached, integrated (e.g., as a design or sticker), or otherwisecoupled with any surface or portion of any mobile device case.

V. Terminology

Many other variations than those described herein will be apparent fromthis disclosure. For example, depending on the embodiment, certain acts,events, or functions of any of the algorithms described herein can beperformed in a different sequence, can be added, merged, or left outaltogether (e.g., not all described acts or events are necessary for thepractice of the algorithms). Moreover, in certain embodiments, acts orevents can be performed concurrently, e.g., through multi-threadedprocessing, interrupt processing, or multiple processors or processorcores or on other parallel architectures, rather than sequentially. Inaddition, different tasks or processes can be performed by differentmachines and/or computing systems that can function together.

The various illustrative logical blocks, modules, and algorithm stepsdescribed in connection with the embodiments disclosed herein can beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. The described functionality can be implemented invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the disclosure.

The various illustrative logical blocks and modules described inconnection with the embodiments disclosed herein can be implemented orperformed by a machine, such as a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor can be a microprocessor,but in the alternative, the processor can be a controller,microcontroller, or state machine, combinations of the same, or thelike. A processor can also be implemented as a combination of computingdevices, e.g., a combination of a DSP and a microprocessor, a pluralityof microprocessors, one or more microprocessors in conjunction with aDSP core, or any other such configuration. Although described hereinprimarily with respect to digital technology, a processor may alsoinclude primarily analog components. For example, any of the signalprocessing algorithms described herein may be implemented in analogcircuitry. A computing environment can include any type of computersystem, including, but not limited to, a computer system based on amicroprocessor, a mainframe computer, a digital signal processor, aportable computing device, a personal organizer, a device controller,and a computational engine within an appliance, to name a few.

The steps of a method, process, or algorithm described in connectionwith the embodiments disclosed herein can be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module can reside in RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, harddisk, a removable disk, a CD-ROM, or any other form of non-transitorycomputer-readable storage medium, media, or physical computer storageknown in the art. An example storage medium can be coupled to theprocessor such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium can be integral to the processor. The processor and the storagemedium can reside in an ASIC. The ASIC can reside in a user terminal. Inthe alternative, the processor and the storage medium can reside asdiscrete components in a user terminal.

Conditional language used herein, such as, among others, “can,” “might,”“may,” “e.g.,” and the like, unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain embodiments include, while other embodiments donot include, certain features, elements and/or states. Thus, suchconditional language is not generally intended to imply that features,elements and/or states are in any way required for one or moreembodiments or that one or more embodiments necessarily include logicfor deciding, with or without author input or prompting, whether thesefeatures, elements and/or states are included or are to be performed inany particular embodiment. The terms “comprising,” “including,”“having,” and the like are synonymous and are used inclusively, in anopen-ended fashion, and do not exclude additional elements, features,acts, operations, and so forth. Also, the term “or” is used in itsinclusive sense (and not in its exclusive sense) so that when used, forexample, to connect a list of elements, the term “or” means one, some,or all of the elements in the list. Further, the term “each,” as usedherein, in addition to having its ordinary meaning, can mean any subsetof a set of elements to which the term “each” is applied.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the devices or algorithms illustrated can be madewithout departing from the spirit of the disclosure. As will berecognized, certain embodiments of the inventions described herein canbe embodied within a form that does not provide all of the features andbenefits set forth herein, as some features can be used or practicedseparately from others.

What is claimed is:
 1. A method for measuring distance, the methodcomprising: providing a distance marker having a tracking image;positioning the distance marker at a selected first location;photographically capturing the image of the distance marker at a secondlocation using a mobile device; and analyzing the captured image usingthe mobile device to determine a distance between the first and secondlocations.
 2. The method of claim 1, wherein the process of analyzingthe captured image using the mobile device to determine a distancebetween the first and second locations further comprising: receiving avideo frame that includes the captured image of the distance marker. 3.The method of claim 2, wherein the process of analyzing the capturedimage using the mobile device to determine a distance between the firstand second locations further comprising: receiving a distance vectorrepresenting a distance between the first and second locations,expressed in image processing units.
 4. The method of claim 3, whereinthe process of analyzing the captured image using the mobile device todetermine a distance between the first and second locations furthercomprising: computing a magnitude of the distance vector to obtain adistance value in image processing units.
 5. The method of claim 4,wherein the process of analyzing the captured image using the mobiledevice to determine a distance between the first and second locationsfurther comprising: converting the distance value to standardmeasurement units.
 6. The method of claim 5, wherein the process ofanalyzing the captured image using the mobile device to determine adistance between the first and second locations further comprising:outputting the distance between the first and second locations to adisplay of the mobile device.
 7. The method of claim 1, furthercomprising: attaching the distance marker to a mobile device case. 8.The method of claim 1, further comprising: installing a softwareapplication to the mobile device.
 9. The method of claim 8, wherein thesoftware application is configured to calculate the distance from themobile device to the image as the distance changes over time in a videoand output the distance as the distance changes over time forpresentation to a user.
 10. The method of claim 1, wherein the image isintegral with a mobile device case.
 11. A method for measuring distance,the method comprising: preparing a mobile device case configured toreceive a mobile device; and installing a software application to themobile device, the software application is configured to be implementedby the mobile device and to detect an image associated with the mobiledevice case, the software application comprising a distance calculatorconfigured to calculate a distance from the mobile device to the image.12. The method of claim 11, wherein the image is integral with themobile device case.
 13. The method of claim 12, wherein the softwareapplication is further configured to calculate the distance from themobile device to the image as the distance changes over time in a videoand output the distance as the distance changes over time forpresentation to a user.
 14. The method of claim 13, wherein the image isaffixed to a distance marker configured to be coupled with the mobiledevice case.
 15. A method for measuring distance, the method comprising:positioning an image at a selected first location; photographicallycapturing the image at a second location using a mobile device;receiving a video frame that includes the captured image; receiving adistance vector representing a distance between the first and secondlocations, expressed in image processing units; computing a magnitude ofthe distance vector to obtain a distance value in image processingunits; converting the distance value to standard measurement units; andoutputting the distance between the first and second locations to adisplay of the mobile device.
 16. The method of claim 15, furthercomprising: providing a distance marker comprising the image.
 17. Themethod of claim 15, further comprising: installing a softwareapplication to the mobile device.
 18. The method of claim 17, whereinthe software application is configured to calculate the distance fromthe mobile device to the image as the distance changes over time in avideo and output the distance as the distance changes over time forpresentation to a user.
 19. The method of claim 15, wherein the image isaffixed to a distance marker configured to be coupled with a mobiledevice case.
 20. The method of claim 15, wherein the image is integralwith a mobile device case.